I'm so sorry about the cancer diagnosis
:sad: I have my
it is the lowest grade possible
I wish you to have many many more good years with Howie
If you haven't already I would suggest a read through
http://harpsie.com/cancer.htm, it is a site written by a regular person whose cat had cancer, lots of good tips/info in there.
One thing with diet, is finding a higher protein, higher fat but low to no carb diet as cancer seems to "feed off" of carbs.